Changing flights out of a different airport

Has anyone switched flights before? We found a cheaper flight out of another airport and wanted to switch and then maybe stay in Jamaica another night! Wondering if this is possible and how it works if you find a cheaper flight..thanks all!

Nevermind, everyone! We were able to do it. Luckily, our flight got changed (which is why we were looking at different flights int he first place), we were able to get a refund on our first booking. We then were able to book out of a different airline, which ended up being cheaper and closer to home! Soooooooo now we get an extra day at CSA!! SO HAPPY!